Apparatus for use in replenishing bobbin underthread in a lock stitch sewing machine



3,490,402 ERTHREAD Jan. 20, 1970 s. J. KETTERER BIN UND CHINE APPARATUS FOR USE IN REPLENISHING BOB IN A LOCK STITCH SEWING MA 3 Sheets-Sheet 1 Filed DeC. l2, 1967 I N VEN TOR. Scniey J. Keerer S. J. KETTERER Jan. 2o, 1970 3,490,402

APPARATUS FOR USE IN REPLENISHING BOBBIN UNDERTHREAD IN A LOCK STITCH SEWING MACHINE 3 Sheets-Sheet 2 Filed Dec. l2, 1967 INVENTOR, Seniey J. Kaerer HQ@ BY M/f( gum wsTNEss; #ma 45664524 3,490,402 THREAD Jan. 20, 1970 s. J. KETTERER APPARATUS FOR USE IN REPLENISHING BOBBIN UNDER IN A LOCK STITCH SEWING MACHINE 3 Sheets-Sheet 5 Filed Dec. 12, 1967 INVENTOR. Sunley J. Keier United States Patent O U.S. Cl. 112--184 12 Claims ABSTRACT OF THE DISCLOSURE Lock stitch sewing machine apparatus for use in replenishing the thread of a bobbin thereof while the bobbin is maintained in place within its thread case within a loop taker is described as utilizing to advantage the manual dexterity and skill of a sewing machine operator to avoid the need for mechanically complex mechanisms which intrinsically require the seizure of a thread loop by the loop taker of the machine to initiate bobbin thread replenishment. Basic to apparatus according to the invention is a system of guides whereby the sewing machine operator may, for example, with replenishment thread in hand, swing such hand RIGHT-LEFT-RIGHT the replenishment thread being thereby so lpositioned that operation thereafter of the sewing machine will cause the replenishment thread to be wound on the bobbin, and this without ever seizing a loop of thread by means of the machines loop taker.

BACKGROUND OF THE INVENTION Field of the invention The invention is directed to lock stitch sewing machine apparatus, and in particular to apparatus and techniques for replenishing the bobbin underthread thereof while such bobbin is maintained in place within its bobbin case.

Description of the prior art To date, various techniques have been employed to wind thread on the bobbin of a lock stitch sewing machine without removing such bobbin from the place wherein it usually resides during ordinary sewing operations. See U.S. Patents Nos. 3,096,736, 3,115,810 and 3,115,855, all assigned to the instant assignee, for typical examples of the Various bobbin winding techniques known so far. What is common to each of these patent references, and what is not at all necessary to apparatus according to this invention, is the requirement for the seizure of a loop of thread at the start of each winding operation. To be more specific, see for example U.S. Patent No. 3,115,855 as most representative of the prior bobbin replenishment techniques. U.S. Patent No. 3,115,- 855 indicates a comparatively complex (and expensive) mechanical arrangement of parts including a bobbin driver which may be selectively engaged to rotate the bobbin independently of its case. With the bobbin driver of such reference engaged, and with the free end of the needle thread thereof firmly anchored, a loop of thread Patented Jan. 20, 1970 is seized by the beak of the machines loop taker as such loop taker is driven in its usual way. The loop taker carries the thread loop about the bobbin case, during which time such loop gets urged, by means of a camming action, between the flanges of the bobbin and gets wedged thereto at the hub of the bobbin, the anchored limb of thread being thereafter automatically cut by a knife edge that is driven rotationally with the bobbin. Loop seizureand eventual bobbin winding-will ordinarily be effected by this technique provided, of course, that the anchored thread limb is rmly held in place at least until such thread limb is cut by the rotating knife. Independent of the anchoring of the free limb of needle thread, however, the seizure of a loop of thread canand sometimes does-fail to occur, thereby preventing bobbin replenishment; `so too, should the anchored limb be too loosely held, the loop taker will simply pull through the loop that has been presented to it, thereby preventing the thread loop from being directed to the hub of bobbin, and permitting the thread to flap about within the loop taker compartment with attendantly, failure to wind thread on the machines bobbin.

Aside from the above described functional shortcomings of the techniques so far known to those skilled in the art, the techniques of the prior art have an additional shortcoming, viz, that the sewing machine operator ordinarily has no concept of what is taking place within the machine in question during bobbin thread replenishment and, therefore, should replenishment fail to occur for any reason whatsoever, the operator will ordinarily be completely at a loss to remedy the situation. In other words, the practice, as has been suggested, of wrapping the free limb of needle thread about the presser foot adjustment screw, to anchor same for loop seizures purposes, is a completely incongruous act which has no meaning to the ordinary sewing machine operator, and hence the skill and dexterity common to most sewing machine operators is not utilized in any way in the replenishment of thread on an expired bobbin.

SUMMARY OF THE INVENTION Rather than employ the loop taker of a sewing machine to initiate the placing of thread on a bobbin rotatable within its bobbin case, the present invention suggests mechanically simple and inexpensive means by which the skill of the sewing machine operator may be employed to advantage to guide manually and visually the replenishment thread to the bobbin for securing thereto. In this way the sewing machine operator can meaningfully see precisely what manipulations are required for bobbin thread replenishment, and should such replenishment fail to occur, the reason therefor will be apparent by a quick inspection of the parts in question.

In its presently preferred form, the invention employs a scheme somewhat like the one indicated in co-pending application Serial No. 575,594, filed in the name of Stanley J. Ketterer, now U.S. Patent No. 3,407,760, dated Iune 4, 1968, and assigned to the instant assignee. That is, a bobbin driver may be selectively engaged so that when the machine in question is set for bobbin thread replenishment, the bobbin will rotate in a direction counter to the direction of loop taker rotation. The bobbin of this, the presently preferred embodiment of the invention, is provided with a thread securing element, which in this case is a radial slot in one of its flanges; and the machine of such preferred embodiment is provided with a system of guides to aid the machine operator in properly manually setting the replenishment thread prior to the winding operation. With the eye of the machines needle below the level of the machines throat plate, two limbs of thread emanate from theneedle aperture in the throat plate, to wit, the supply limb and the free limb. The machine operator, with the free limb in hand, pulls that thread limb through a throat plate guide to a point below such throat plate, and thence by additional guides carries the free limb of thread under a thread tension spring and across the slotted bobbin flange. The operator then sets the machine into operation, still firmly holding the free limb in hand, or anchoring same, whereby as the bobbin is rotated counter to the machines loop taker, the thread residing across the face of the bobbin flange drops into the bobbin slot. As the bobbin is continued to be rotated, thread is drawn from the needle supply and wound on the bobbin; and ultimately the free limb is cut against an edge provided on one of the guides. Note should be made that with such a technique, the loop taker takes no functional part whatsoever in the replenishment of bobbin thread, and that as a result thereof, no delicate relationship involving the loop taker must be maintained during bobbin thread replenishment.

A principle object of the invention is to provide apparatus for use in replenishing underthread on a bobbin that is maintained in place within its bobbin case without need for the seizure of a loop of supply thread by the machines loop taker.

Another object of the invention is to provide means by which supply thread may be manually guided to a bobbin for the replenishment of thread. thereon while such bobbin resides in its bobbin case.

Another object of the invention is to provide, in a sewing machine, guide apparatus for use in 4manually placing a free limb of supply thread with respect to a bobbin within its case that operation thereafter of the sewing machine will result, not in the seizure of a loop by the machines loop taker, but rather will effect replenishment of thread on such bobbin.

The invention will be described with reference to the gures, wherein:

FIG. 1 is a side elevational view partly in section, of a portion of a sewing machine incorporating the invention,

FIG. 2 is a front elevational view, partly in section, of the sewing machine of FIG. l,

FIG. 3 is a perspective view of a presently preferred throat plate useful with the invention,

FIG. 4 is an exploded view showing the assemblage of parts constituting the preferred form of the invention,

FIGS. 5-8 constitute a series of views useful in describing how apparatus according to the invention may be used to replenish, handily, a bobbin in place within its thread case, and

FIG. 9 is a View useful in conjunction with FIGS. 5-8 to describe the functioning of apparatus according to the invention.

Since the invention is directed to in-place bobbin thread replenishment, only so much detail of a sewing machine as is necessary for a full understanding of the invention is indicated and described, it being understood that the machine described as embodying the invention is equipped 'with the usual bed plate, standard, bracket arm, and a full complement of mechanisms to drive the feed dogs, thread takeup, and loop taker according to certain timed relationships.

With reference then to FIGS. 1-4, the throat plate 10 of the sewing machine in question is provided with elongated apertures 11 through which the feeds dogs 12 of, say, a four-motion drop feed mechanism may project for coaction with work fabric 16 held between the feed dogs 12 and a presser foot 14. Forward of the throat plate 10 in the direction of fabric feed is a slide plate 18 that is equipped with a notch 20 to aid an operator in sliding the plate 18 in the direction of the arrow on FIG. l, thereby to expose, to the View of the operator, the machines loop taker 22, which in this case is a vertical axis rotary hook.

The loop taker 22 includes a generally canister-shaped hook body 24, and is provided with a loop-seizing beak 26 that is disposed at one side of a gap 28 in such hook body 24. A shoulder 30` obtains within the hook body 24, and serves as one-half the raceway for a bearing rib 32 on a thread case 34. The bearing rib 32 rests atop the shoulder 30 of the hook body 24, and is provided with a gap 36 arcuately equivalent to the gap 28l in the hook body 24, whereby the edges 38 and 40 at the extremities of the gap 36 serve, respectively, as ingoing and outgoing pockets for the passage of thread about the thread case during usual sewing operations.

The thread case 34 has an inwardly tapering lower half 42 into which the flange 44 of a bobbin 46 is adapted to seat. Upstanding from the bearing rib 32 of the thread case 34 is a generally cylindrical wall 48 that is provided with a curved recess 50 and a cutout 52: the recess 50 facilitates removal of the bobbin 46 from the thread case; and the cutout 52 serves as a thread guide for issuing funderthread from the bobbin during sewing` A flat thread tension spring 54, upwardly creased at 56 and downwardly creased at 58, bridges the thread case cutout 52, and such spring 54 is secured to the thread case 34 by means of a screw 60. The tension of the spring 54 against the underthread is adusta-ble by means of a screw 62. A thread guide arm 64, secured to the thread case 34 by ymeans of a screw 65, embraces the thread tension spring 54, projects above the upper rim of the thread case wall `48, and serves for manually positioning replenishment thread from a supply to beneath the tension spring 54 for winding thereof on the bobbin 46. This will be more fully appreciated later.

The edges 38 and 40 of the thread case gap 36, which serve as ingoing and outgoing pockets for thread loops manipulated during sewing operations, are slightly tapered to accommodate the abutment surfaces 68 and 70 respectively of a thread case rotation restraining mechanism 72. The rotation restraining mechanism 72 includes a strap piece 74 that embraces an eccentrically disposed shoulder 75 within the hook body 24, and such strap piece is constrained to move to-and-fro into the thread case gap 36 by means of a plate 76. The plate 76, which as will be appreciated later, is mechanically grounded to the frame of the sewing machine, being provided with channels 78 that embrace arms 79 on the strap piece 74 to prevent rotation of the strap piece 7-4 with the loop taker 22, and to effect the aforesaid to-and-fro movement.

To provide an upper raceway surface for the bearing rib 32 of the thread case, an almost annular gib 80, of slightly larger dimension than the hook body 24, is adapted to snap onto the hook body 24, a flange 84 on the gib snugly residing in a generally annular recess 86 on the hook body 24 so that the gib 80 and hook body 24 are rotatable as an integral unit. The gib 80 is provided with an inwardly protruding surface 88, which is useful as a thread camming surface to pull-off underthread from the bobbin 446 during sewing. In addition, an index marker appears on the upper surface of the gib 80 and, since the loop taker 22 and the machines needle 92 operate in accordance with a certain timed relationship therebetween, the rotational position of the index marker 90 relative to a reference marker 90 on the sewing machine frame (see FIG. 5) is a reflection of the precise needle position when the eye of the needle 92 is below the level of the throat plate 10, and not visible to the operator.

In this, the presently preferred embodiment of the invention, the upper flange 9'4 of the bobbin is provided with a radial slot 96; and the hub 98 of the bobbin 46 is provided with a screwhead notch 100 that projects through the lower ange 44 of the bobbin 46.

The loop taker 22 is rotatable about the thread case 34 by means of a gear 102 that meshes with a gear 104 secured to a boss 106 on the hook body 24. The gear 102 is rotatable in a journal bearing 108 that is supported in a web 110 within the bed of the sewing machine.

A journal 112, housed within the boss 106 and projecting through the hook body '24 and the strap piece 74, secures to the plate 76, the journal 112 having a bushing 114 secured thereto by a set screw 116. The bushing 114 is provided with a shoulder 118 that gets secured to a web 120 of the sewing machine by means of a screw 122, thereby constraining the assemblage of parts 112, 74 and 76 against rotation with the loop taker 22.

The bearing surface 124 of the journal 112 is slightly greater than semicircular in cross section, and such surface 124 slidably and rotationally accommodates a bobbin drive shaft 126. The bobbin drive shaft 126 is prO- vided with a keyed head 128 that may, depending on whether the bobbin drive shaft 126 is moved upwardly, mesh with the notch 100 in the bobbin 46. A bevel gear 130 is force-tit on the bobbin drive shaft 126, and the limbs 132 of a forked lever 134 are adapted to reside between a shouldered head 136 on the shaft 126 and the gear 130. By pivoting the lever 134 vertically upward about its fulcrum point 138, the gear 130-bobbin drive shaft 126 assembly may be raised both to mesh the gear 130 with the gear 102, and to seat the keyed head 128 of the shaft 126 with the bobbin notch 100; pivoting the lever vertically downward disengages the gears 102, 130 and the keyed head and bobbin notch 128, 100. Note should be taken that the gears 104 and 130 are counterrotatable with respect to each other by means of the gear 102 and that, therefore, the loop taker 22 and the bobbin 46 will counterrotate during bobbin replenishment, such serving to keep the replenishment thread under the tension spring 54 during the winding procedure.

Disposed within the sewing machine housing for the loop taker assembly is an assemblage of parts for use in initiating the bobbin thread replenishment operation. This assemblage includes a swing arm 140 keyed to a shaft 142, by means of a screw 144, for rotation thereof. The arm 140 is equipped with a thread guide 141; and be tween the arm 140 and the guide 141, a thread wedge 143 is provided. The shaft 142 is provided with a shoulder 146 having a slot 148. The shoulder 146 of the shaft 142 is adapted to rest against the web 120, and the shaft 142 is rotatable Within defined limits in a bushing 150, which bushing 150 has an enlarged head 152. The fulcrum point 138 for the lever 134 is provided by oppositely disposed tangs 154, 156, the tang 154 abutting the head 152 of the bushing 150, and the tang 156 abutting the top face 157 of a force-producing washer 158. The washer 158 is notched to accommodate a spring 160 that is anchored to the frame of the sewing machine at a point 162, whereby the swing arm 140 is biased to the position indicated in phantom on FIG. 5. Pivotally secured to the underface of the force producing washer 158 by means of a screw 164 is a curved arm 166 that is adapted to hook into a slot 168 in the lever 134. When the shaft 142 is rotated in one direction the portion 170 of the arm 166 pushes on the lever 134 to turn the lever about its fulcrum 138, thereby raising the bobbin drive shaft 126-gear 130 assembly for thread replenishment purposes; when the shaft 142 is rotated in the opposite direction, the portion 172 of the arm 166 pulls on the lever 134 to lower the bobbin drive shaft 126-gear 130 assembly.

To maintain the swing arm 140 in place, i,e. to keep the bobbin replenishment apparatus engaged until its release is desired, a latch assembly is provided and includesa latch arm 174 pivotally mounted to the frame of the sewing machine by means of a screw 175. The latch arm 174 is biased by means of a spring 176 so that a tang 178 on the arm 174 will ride on the shoulder 146 and will latch into the slot 148 when the shaft 142 is sufficiently rotated by means of the swing arm 140.

An important part of this, the presently preferred form of the invention, is in the form and nature of the throat plate 10, with reference in particular to FIG. 3, the throat plate 10 is shown provided with a thread slot 182 that runs between the forward edge 183 of the throat plate 10 and the needle aperture 184 of the throat plate. The slot 182 is inclined in the direction of the eye of the needle 92 when the needle is below the level of the throat plate 10 so as to facilitate, for bobbin replenishment purposes, the manual carrying of the free limb of needle thread to the guides 64, 141 for `coupling that thread limb to the bobbin 46. A at spring 186 secures to the upper face of the throat plate 10, by means of a screw 188, and serves to prevent interference between the slot 182 with the needle thread during sewing.

OPERATION To appreciate the manner rby which the invention utilizes the manual dexterity and skill of a sewing machine operator, without requiring much more than a RIGHT- LEFT-RIGHT swing of the hand, to replenish a bobbin in place within its thread case, reference should now be had to FIGS. 5-9:

(l) With the bobbin underthread expended, the operator rst slides the slide plate 18 forwardly to expose the expired bobbin, the loop taker assembly, and the replenishment mechanism.

(2) Then, with the swing arm 140 in its usual position as indicated by the phantom lines of FIG. 5, the operator pushes, by means of a nger, the swing arm so that the arm 140 occupies the position indicated by solid lines on FIG. 5. In so fingering the swing arm 140, the shaft 142 gets rotated against the tension of the spring 160, and ultimately the tang 178 drops into the shaft slot 148 to hold the swing arm 140 so positioned. In rotating the shaft 142, the portion of the curved arm 166 pushes against the lever 134, pivoting the lever 134 about its fulcrum 138, and causing the gear 130 and bobbin drive shaft 126 to lift, whereby the gear 130 will mesh with the gear 102, and whereby the keyed head 128 of the shaft 126 will seat within the notch 100 of the bobbin 46. In the event the keyed head 128 of the bobbin drive shaft 126 and the bobbin notch 100 do not at rst lock together (which will probably be the usual case), rotation of the bobbin drive shaft 126 by something less than degrees will automatically snap the two parts in question together for unitary rotation by the gear 102. Aside from serving to actuate the bobbin replenishing mechanism, the swing arm 140 serves the additional purpose of holding the bobbin down so that it will not be lifted by the bobbin drive shaft 126 as such shaft itself is lifted.

(3) The operator then positions the threaded sewing machine needle 92, e.g. by hand-turning the balance wheel of the machine, so that the loop taker index marker 90 registers with the reference marker 9.0' on the sewing machine frame, at which time the eye of the needle 92 will be positioned below the level of the throat plate 10 as indicated in FIG. 9. Now, the operator is ready for (her) RIGHT-LEFT-RIGHT swing of (her) hand, after which the operation of the sewing machine will result in in-place bobbin thread replenishment (and this without ever requiring the manipulation of a loop of thread by the loop taker of the machine).

(4) With the eye of the needle 92 so positioned, as in step 3 above, two limbs of thread emanate from the throat plate needle aperture 184, viz the supply limb Ts and the free limb Tf. The free limb Tf is then taken in hand and manually carried to the right so that it rests in line with a small space 200 between the flat spring 186 and the throat plate 10.

Then the free limb of thread is manually swung to the left, and while this is being done (see FIG. 5) the limb Tf rides down the inclined slot 182 of the throat plate 10, passes to below the level of the throat plate, and ends up at the thread position indicated in phantom on FIG. 6.

' (6) The thread limb Tf is then manually swung back to the right, this causing the thread to be guided by the guide arm 64v to below the thread tension spring S4 as in FIG. 6, and to be urged by the guide 141 (see FIG. 7) to the thread wedge 143 as in PIG. 8.

(7) Operation of the sewing machine thereafter causes the bobbin to rotate, the free limb of thread Tf ultimately dropping into the slot 96 in the bobbin flange 94 (see FIG. 8), and as the bobbin continues to rotate it draws replenishment thread through the eye of the needle 92. Since the free limb Tf of the thread is anchored at the thread wedge 143, rotation of the bobbin 46 puts successive twists into the free limb Tf of thread, and ultimately, but quickly, the free limb is cut against the edge of the guide 141.

(8) After the bobbin is replenished with thread, as desired, operation of the sewing machine is stopped. The slide plate 18 is returned to its position overlying the loop taker compartment and, as the slide plate is so positioned, it engages the latch arm 174, thereby rotating such arm 174 about the axis of the screw 175, and causing the tang 178 to lift out of the slot 148 of the shaft 142 and permitting the swing arm 140 to return, in response to the tension of the spring 160, to the position indicated in phantom in FIG. 5.

While the invention has been described in its preferred form it is to be understood that the words which have been used are words of description rather than of limitation and that changes may be made without departing from the true scope and spirit of the invention. For example, it would be Well within the purview of the invention to employ an auxiliary thread supply which, by means of a system of guides, may be used for in-place bobbin thread replenishment, and such without the loop seizure and thread manipulation common to the known in-place bob-bin thread replenishment schemes.

Also, for example, it would be within the scope of the invention to modify the bobbin which has been herein shown and described so that the replenishment thread may be secured thereto by some other, but equally convenient, means.

Having thus set forth the nature of this invention, what is claimed herein is:

1. In conjunction with a lock stitch sewing machine having a needle (92), throat plate (10), and loop taker (22), said loop taker (22) including a thread case (34) and a bobbin (46) therein for accommodating underthread thereon, and wherein said machine is of the type having respective means (104, 130) for seiectively rotationally driving said loop taker (22) and said bobbin (46) relative to said thread case (34), whereby selectively thread may be replenished on said bobbin (46) while said bobbin is maintained in place within its said thread case (34), the improvement wherein:

(a) said bobbin (46) includes means for receiving thread guided to and rmly held about the hub of said bobbin, and

(b) wherein said machine is provided with guide means (64, 141) for use in manually guiding thread from a supply thereof to the hub of said bobbin (46) and for firmly holding said thread thereon.

2. The apparatus of claim 1 wherein said guide means (64, 141) provides at least one surface along which and against which said thread may be manually urged for 8 coupling thereof about the hub of said bobbin (46).

3. The apparatus of claim 1 wherein:

(a) saidthre'ad supply is the needle thread supply, and

(b) wherein said throat plate (10) is provided with a guide (182) for use, when the eye of said needle (92) is below the level of said throat plate (10), in manually guiding that limb (T f) of needle thread, which does not lead to said needle thread supply, to said guide means (64, 141), whereby said limb (Tf) of thread may be directed to and firmly held about the hub of said bobbin (46).

4. The apparatus of claim 3 1 (a) wherein said throat plate (10) is provided with a slot (182) extending from the needle aperture (184) of said throat plate (10) to a peripheral edge (183) of said throat plate (10), and

(b) wherein said guide means (64, 141) is adapted to receive thread urged to issue from said slot (182), said guide means being further adapted to provide a surface along which thread may be drawn for coupling about the hub of said bobbin (46).

S. The apparatus of claim 4 (a) wherein said thread case (34) is of the type having a thread tension spring (54) from under which said underthread is adapted to issue, and

(b) wherein said guide means (64, 141) includes at least one member (64) for use in manually urging thread to pass under said tension spring (54),

whereby when the eye of the said needle (92) is below the level of said throat plate (10), that limb (Tf) of thread which does not lead to the needle thread supply may be manually seized and pulled along the said guide member (64) to pass under the said tension spring (54).

6. The apparatus of claim 5 wherein said guide means includes at least one other member (141) for use in defining the orientation of the said limb (Tf) of thread prior to replenishment of said bobbin (46).

7. The apparatus of claim 5 (a) wherein the said respective means (104, for selectively rotationally driving the loop taker (22) and bobbin (46) relative to said thread case (34) are adapted to counterrotate said loop taker (22) and said bobbin (46),

(b) wherein said guide means (64, 141) includes at least one other member (141) for use defining the orientation of said limb (Tf) prior to replenishment of said bobbin (46), and

(c) wherein said bobbin (46) is provided with a slot (96) into which said limb (Tf) may drop when said bobbin is rotated relative to said thread case (34).

8. The apparatus of claim 6 including (a) a shaft (142),

(b) an arm on said shaft (142) adapted to swing said shaft (142) about its axis, and

(c) means (126) for rotationally driving said bobbin (46), said means (126) for driving said bobbin being coupled to and actuable by said shaft (42),

said arm (140) on said shaft (142) being so disposed as to prevent removal of said bobbin (46) from said thread case (34) when said means (126) for rotationally driving said bobbin (46) is actuated.

9. The apparatus of claim 8 (a) wherein said bobbin (46) is provided with an axially disposed notch (100), and

(b) wherein said means (126) for rotationally driving said bobbin includes a shaft (126) coaxially disposed with respect to the rotational axis of the said loop taker (22), and wherein said shaft (126) is adapted to key with said notch (100) in said bobbin (46).

10. The apparatus of claim 9 wherein said one other member (141) for use in defining the orientation of the limb (Tf) of thread is coupled to said arm (140) and is positionable therewith.

11. The apparatus of claim 4 wherein said slot (182) in said throat plate (10) is disposed to incline in the direction of the eye of the needle (92) when said eye of said needle (92) is at a predetermined point below the level of said throat plate (10).

12. The apparatus of claim 4 (a) including means (80) providing an index (90) rotational with said loop taker (22), and* (b) including means providing a reference marker (90') against which said index marker (90) is relatively positionable,

the relationship between said reference marker (90') and said index (90) thereby defining the position of the eye marker 5 of the needle (92) of said machine relative to the level of the throat plate (100) of said machine.

References Cited UNITED STATES PATENTS 3,106,176 10/1963 Doerwer 112-181 XR 3,115,855 12/1963 Ketterer 112-184 H. HAMPTON HUNTER, Primary Examiner U.S. Cl. X.R. 112-186, 252 

